Suppression Of Androgen Production Research Articles

Integrated Studies on Male Reproductive Toxicity of Bis(2-ethylhexyl)-tetrabromophthalate: in Silico, in Vitro, ex Vivo, and in Vivo.

Bis(2-ethylhexyl)tetrabromophthalate (TBPH) has been widely detected in the environment and organisms; thus, its toxic effects on male reproduction were systematically studied. First, we found that TBPH can stably bind to the androgen receptor (AR) based on in silico molecular docking results and observed an antagonistic activity, but not agonistic activity, on the AR signaling pathway using a constructed AR-GRIP1 yeast assay. Subsequently, we validated the adverse effects on male germ cells by observing inhibited androgen production and proliferation in Leydig cells upon in vitro exposure and affected general motility and motive tracks of zebrafish sperm upon ex vivo exposure. Finally, the in vivo reproductive toxicity was demonstrated in male zebrafish by reduced mating behavior in F0 generation when paired with unexposed females and abnormal development of their offspring. In addition, reduced sperm motility and impaired germ cells in male zebrafish were also observed, which may be related to the disturbed homeostasis of sex hormones. Notably, the specifically suppressed AR in the brain provides further evidence for the antagonistic effects as above-mentioned. These results confirmed that TBPH affected male reproduction through a classical nuclear receptor-mediated pathway, which would be helpful for assessing the ecological and health risks of TBPH.

AndroPred: an artificial intelligence-based model for predicting androgen receptor inhibitors

Androgen receptor (AR), a steroid receptor, plays a pivotal role in the pathogenesis of prostate cancer (PCa). AR controls the transcription of genes that help cells avoid apoptosis and proliferate, thereby contributing to the development of PCa. Understanding AR molecular mechanisms has led to the development of newer drugs that inhibit androgen production enzymes or block ARs. The FDA has approved a small number of AR-inhibiting drugs for use in PCa thus far, as the identification of novel AR inhibitors is difficult, expensive, time-consuming, and labor-intensive. To accelerate the process, artificial intelligence (AI) algorithms were employed to predict AR inhibitors using a dataset of 2242 compounds. Four machine learning (ML) and deep learning (DL) algorithms were used to train different prediction models based on molecular descriptors (1D, 2D, and molecular fingerprints). The DL-based prediction model outperformed the other trained models with accuracies of 92.18% and 93.05% on the training and test datasets, respectively. Our findings highlight the potential of DL, particularly the DNN model, as an effective approach for predicting AR inhibitors, which could significantly streamline the process of identifying novel AR inhibitors in PCa drug discovery. Further validation of these models using experimental assays and prospective testing of newly designed compounds would be valuable to confirm their predictive power and applicability in practical drug discovery settings. Communicated by Ramaswamy H. Sarma

Saracatinib synergizes with enzalutamide to downregulate AR activity in CRPC.

Prostate cancer (PCa) remains the most diagnosed non-skin cancer amongst the American male population. Treatment for localized prostate cancer consists of androgen deprivation therapies (ADTs), which typically inhibit androgen production and the androgen receptor (AR). Though initially effective, a subset of patients will develop resistance to ADTs and the tumors will transition to castration-resistant prostate cancer (CRPC). Second generation hormonal therapies such as abiraterone acetate and enzalutamide are typically given to men with CRPC. However, these treatments are not curative and typically prolong survival only by a few months. Several resistance mechanisms contribute to this lack of efficacy such as the emergence of AR mutations, AR amplification, lineage plasticity, AR splice variants (AR-Vs) and increased kinase signaling. Having identified SRC kinase as a key tyrosine kinase enriched in CRPC patient tumors from our previous work, we evaluated whether inhibition of SRC kinase synergizes with enzalutamide or chemotherapy in several prostate cancer cell lines expressing variable AR isoforms. We observed robust synergy between the SRC kinase inhibitor, saracatinib, and enzalutamide, in the AR-FL+/AR-V+ CRPC cell lines, LNCaP95 and 22Rv1. We also observed that saracatinib significantly decreases AR Y534 phosphorylation, a key SRC kinase substrate residue, on AR-FL and AR-Vs, along with the AR regulome, supporting key mechanisms of synergy with enzalutamide. Lastly, we also found that the saracatinib-enzalutamide combination reduced DNA replication compared to the saracatinib-docetaxel combination, resulting in marked increased apoptosis. By elucidating this combination strategy, we provide pre-clinical data that suggests combining SRC kinase inhibitors with enzalutamide in select patients that express both AR-FL and AR-Vs.

AMH inhibits androgen production in human theca cells

Both excessive ovarian production of AMH and androgen are important features of polycystic ovary syndrome (PCOS). Present study aimed to explore the direct effect of AMH on androgen production in human theca cells. Primary cultured human theca cells were treated with AMH, an ALK2 (the BMP type 1 receptor) inhibitor and an ALK5 (the TGFβ type 1 receptor) inhibitor. AMH significantly suppresses the expression of the androgen synthesis-related enzyme CYP17A1 and reduces the production of androstenedione and testosterone in normal human theca cells and PCOS theca cells. Inhibitors of ALK2/3 and ALK5 antagonize the effect of AMH on the expression of CYP17A1. Although both ALK5 and ALK2 interact with AMHR2 in the presence of AMH, AMH activated neither TGFβR-Smads (Smad 2/3) nor BMPR-Smads (Smad 1/5/8). Our data suggested that AMH suppresses androgen synthesis-related enzyme CYP17A1 expression and inhibits androgen production in human theca cells, which process may be mediated by ALK2 and ALK5.

Ibuprofen Reduces Testosterone Level in Women With Polycystic Ovary Syndrome.

ContextHyperandrogenism is a central feature of polycystic ovary syndrome (PCOS). In vitro studies have demonstrated that inflammatory stimuli promote whereas ibuprofen inhibits androgen production by ovarian theca-interstitial cells.ObjectiveThis work aimed to determine the effects of nonselective inhibitor of cyclooxygenases COX-1 and COX-2 on testosterone levels.MethodsA prospective pilot study took place in an academic hospital of women with PCOS defined according to Rotterdam criteria (N = 20). Evaluations were taken at baseline and after 3 weeks of ibuprofen administration (400 mg twice a day or 400 mg 3 times a day, respectively, in women with weight < and ≥ 70 kg). The main outcome measure was total serum testosterone.ResultsIbuprofen administration was associated with a decline of total testosterone from 0.75 ± 0.06 ng/mL to 0.59 ± 0.05 ng/mL (P = .008). There was no statistically significant change in the levels of other relevant hormones including dehydroepiandrosterone sulfate, gonadotropins, and insulin. Multiple regression analysis identified the greatest decline of testosterone was independently predicted by baseline testosterone level (P = .004) and by baseline insulin sensitivity index (P = .03).ConclusionNonselective inhibition of COX-1 and COX-2 leads to selective reduction of testosterone consistent with direct inhibitory effect on ovarian steroidogenesis.

Tributyltin inhibits development of pubertal Leydig cells in rats

Tributyltin (TBT) is extensively applied as an antifouling mediator, and it is well-known as an endocrine disrupting chemical. However, it remains elusive whether TBT can affect the development of pubertal Leydig cells (LCs), as a part of its endocrine mechanism of action. In this study, male Sprague Dawley rats (35-day-old) orally received TBT (0, 1, or 5 mg/kg) for 24 days. Immature LCs (ILCs) were separated from 35-day-old rats, and the cells were exposed to TBT at various concentrations (0, 0.05, 0.5, 1, or 5 μM) for 24 h. In vivo TBT treatment decreased the number of LCs and inhibited androgen production (2.92 ± 0.44, 1.16 ± 0.29, and 0.67 ± 0.10 ng/ml after treatment with TBT at 0, 1, and 5 mg/kg, respectively). In vitro TBT treatment reduced androgen production, cell viability, and cell cycle progression, while increased the levels of reactive oxygen species (ROS) along with subsequent apoptosis, particularly at the concentration of 5 μM. According to in vitro and in vivo findings, TBT downregulated the expression levels of genes that could control steroidogenesis (Hsd17b3, Scarb1, Hsd3b1, and Star), and decreased protein levels due to potential reduction of NR5A1 (Nr5a1). In summary, TBT inhibited cholesterol transport and activities of certain steroidogenic enzymes, thereby leading to the reduction of androgen production.

Second-generation hormonotherapy in prostate cancer and bone microenvironment.

Prostate cancer (Pca) is the most commonly diagnosed cancer affecting men in France. Before the age of 75 years old, 1 in 8 French men will have Pca. Androgen deprivation therapies (ADT) remain the standard of care. Such therapies induce significant bone loss. The bone-remodelling cycle depends on the androgen synthesis signalling pathways. Furthermore, age-specific hormonal decline plays a key role in the decrease in bone mass. As a result, the older the patients, the more likely they are to have osteoporosis if they are treated with hormone therapy. Their risk of osteoporotic fracture has an impact on their quality of life and their capacity of independent living. In recent years, newer hormone therapies (acetate abiraterone, enzalutamide, apalutamide and darolutamide) have proved efficient in metastatic castration-resistant Pca (mCRPC) patients as well as in hormone naïve patients, and actually in nonmetastatic diagnosis. The combination of these treatments with ADT highly inhibit androgen production pathways. They are prescribed to aged patients undergoing bone density loss after first-generation antiandrogen treatment. Specific recommendations for bone health management in Pca patients are currently lacking. To date, bone mineral density in patients treated with second-generation hormone therapy has never been assessed in a prospective study. This review aims at reviewing what is known about the impact of second-generation hormonotherapy on bone microenvironment.

Modeling the synergistic properties of drugs in hormonal treatment for prostate cancer

Prostate cancer is one of the most prevalent cancers in men, with increasing incidence worldwide. This public health concern has inspired considerable effort to study various aspects of prostate cancer treatment using dynamical models, especially in clinical settings. The standard of care for metastatic prostate cancer is hormonal therapy, which reduces the production of androgen that fuels the growth of prostate tumor cells prior to treatment resistance. Existing population models often use patients’ prostate-specific antigen levels as a biomarker for model validation and for finding optimal treatment schedules; however, the synergistic effects of drugs used in hormonal therapy have not been well-examined. This paper describes the first mathematical model that explicitly incorporates the synergistic effects of two drugs used to inhibit androgen production in hormonal therapy. The drugs are cyproterone acetate, representing the drug family of anti-androgens that affect luteinizing hormones, and leuprolide acetate, representing the drug family of gonadotropin-releasing hormone analogs. By fitting the model to clinical data, we show that the proposed model can capture the dynamics of serum androgen levels during intermittent hormonal therapy better than previously published models. Our results highlight the importance of considering the synergistic effects of drugs in cancer treatment, thus suggesting that the dynamics of the drugs should be taken into account in optimal treatment studies, particularly for adaptive therapy. Otherwise, an unrealistic treatment schedule may be prescribed and render the treatment less effective. Furthermore, the drug dynamics allow our model to explain the delay in the relapse of androgen the moment a patient is taken off treatment, which supports that this delay is due to the residual effects of the drugs.

Exposure to di-n-octyl phthalate during puberty induces hypergonadotropic hypogonadism caused by Leydig cell hyperplasia but reduced steroidogenic function in male rats

Humans are exposed to phthalates ubiquitously, which may threaten health. However, whether di-n-octyl phthalate can prevent pubertal sexual maturity is still elusive. In this study, male Sprague Dawley rats (age 35 days) were treated daily by gavage with 0, 10, 100, and 1000 mg/kg body weight of di-n-octyl phthalate from day 35 to day 49 after birth. Di-n-octyl phthalate significantly reduced serum testosterone levels at doses of 100 and 1000 mg/kg, but increased serum luteinizing hormone levels of 1000 mg/kg and decreased testosterone/luteinizing hormone ratio at ≥10 mg/kg, without affecting serum follicle-stimulating hormone levels. Di-n-octyl phthalate significantly induced Leydig cell hyperplasia (increased number of CYP11A1-positive Leydig cells) at 100 and 1000 mg/kg. Di-n-octyl phthalate down-regulates the gene expression of Cyp11a1, Hsd3b1 and Insl3 in individual Leydig cells. Di-n-octyl phthalate can also reduce the number of sperm in the epididymis. Di-n-octyl phthalate increased phosphorylated AKT1/AKT2 without affecting their total proteins, but increased the total protein and phosphorylated protein of ERK1/2 and GSK-3β. Primary immature Leydig cells isolated from 35-day-old rats were treated with 0–50 μM di-n-octyl phthalate for 3 h. This phthalate inhibited androgen production under basal, LH-stimulated, and cAMP-stimulated conditions by 5 and 50 μM in vitro via down-regulating Cyp11a1 expression but up-regulating Srd5a1 expression in vitro. In conclusion, di-n-octyl phthalate induces hypergonadotropic hypogonadism caused by Leydig cell hyperplasia but reduced steroidogenic function and prevents sperm production.

MESENCHYMAL STEM CELLS SECRETOME REGULATES STEROIDOGENESIS AND DECREASES ANDROGEN PRODUCTION IN PCOS CELL MODEL VIA SECRETING BMP-2

Polycystic ovary syndrome (PCOS) is the most common endocrine disorder in women with characteristics of inflammation, hyperandrogenism, and polycystic ovaries. Most available therapies for PCOS aim to regulate the steroidogenesis and decrease ovarian androgen production to enhance fertility. Our previous study shows the ability of human bone marrow mesenchymal stem cells conditioned media (MSC-CM) to inhibit androgen production by human theca-like cell model (H295R cells). Previous studies demonstrated the ability of BMP-2 as a modulator of androgen production and alteration in steroidogenesis pathway enzymes in bovine theca cells.

Eligibility Criteria Related to Hormone Therapy in Acne Clinical Trials: A Systematic Review

Hormones play a complex role in acne pathogenesis and treatment. Androgens typically increase the size and secretion of sebaceous glands, worsening acne, whereas estrogen counters androgen effect by direct local opposition, inhibition of androgen production, and gene regulation (Barros and Thiboutot, 2017; Beinenfeld et al., 2019). Despite multiple guidelines on acne management, there is a paucity of high-quality data on the treatment of acne among patients receiving hormone therapy (Beinenfeld et al., 2019; Del Rosso et al., 2015; Zaenglein et al., 2016).

Associations of Trimester-Specific Exposure to Bisphenols with Size at Birth: A Chinese Prenatal Cohort Study.

Background:Bisphenol A (BPA) is an endocrine disruptor that affects fetal growth in experimental studies. Bisphenol F (BPF) and bisphenol S (BPS), which have been substituted for BPA in some consumer products, have also shown endocrine-disrupting effects in experimental models. However, the effects of BPF and BPS on fetal growth in humans are unknown.Objectives:Our goal was to investigate trimester-specific associations of urinary concentrations of BPA, BPF, and BPS with size at birth.Methods:The present study included 845 pregnant women from Wuhan, China (2013–2015), who provided one urine sample in each of the first, second, and third trimesters. Linear regressions with generalized estimating equations were applied to estimate trimester-specific associations of urinary bisphenol concentrations with birth weight, birth length, and ponderal index. Linear mixed-effects models were used to identify potential critical windows of susceptibility to bisphenols by comparing the exposure patterns of newborns in the 10th percentile of each birth anthropometric measurement to that of those in the 90th percentile.Results:Medians (25th–75th percentiles) of urinary concentrations of BPA, BPF, and BPS were 1.40 (0.19–3.85), 0.65 (0.34–1.39), and 0.38 (0.13–1.11) ng/mL, respectively. Urinary BPA concentrations in different trimesters were inversely, but not significantly, associated with birth weight and ponderal index. Urinary concentrations of BPF and BPS during some trimesters were associated with significantly lower birth weight, birth length, or ponderal index, with significant trend p-values () across quartiles of BPF and BPS concentrations. The observed associations were unchanged after additionally adjusting for other bisphenols. In addition, newborns in the 10th percentile of each birth anthropometry measure had higher BPF and BPS exposures during pregnancy than newborns in the 90th percentile of each outcome.Conclusions:Prenatal exposure to BPF and BPS was inversely associated with size at birth in this cohort. Replication in other populations is needed. https://doi.org/10.1289/EHP4664

Propofol Inhibits Androgen Production in Rat Immature Leydig Cells.

Background: Propofol is a widely used anesthetic. Whether propofol inhibits androgen production by rat Leydig cells and the underlying mechanism remains unclear. The objective of the current study was to examine the effects of propofol exposure to rat primary immature Leydig cells and to define propofol-induced inhibition of steroidogenic enzymes in both rat and human testes in vitro. Methods: Immature Leydig cells were purified from 35-day-old male Sprague–Dawley rats and were exposed to propofol for 3 h. The androgen production by Leydig cells under basal, luteinizing hormone, 8bromo-cAMP, and steroid-substrate stimulated conditions and gene expression of Leydig cells after exposure to propofol were measured. Immature Leydig cells were treated with propofol for 3 h and switched to propofol-free medium for additional 3 and 9 h to test whether propofol-induced inhibition is reversible. 3H-Steroids were used to evaluate the direct action of propofol on cytochrome P450 cholesterol side chain cleavage (CYP11A1), 3β-hydroxysteroid dehydrogenase (HSD3B), cytochrome P450 17α-hydroxylase/17,20-lyase (CYP17A1), and 17β-hydroxysteroid dehydrogenase 3 (HSD17B3) activities in rat and human testes in vitro. Results: Propofol significantly lowered luteinizing hormone and 8bromo-cAMP stimulated androgen production by Leydig cells after 3-h exposure. Further investigation showed that propofol down-regulated the expression of Cyp11a1 and Cyp17a1 and their proteins at 5 and 50 µM, although it up-regulated Lhcgr expression at 50 µM. Propofol significantly suppressed phosphorylation of ERK1/2 and induced ROS production in immature Leydig cells at 5 and 50 µM. Propofol significantly induced apoptosis of immature Leydig cells at 50 µM. Propofol specifically inhibited rat and human testis HSD3B activities in vitro. The half maximal inhibitory concentrations of propofol for rat and human HSD3B enzymes were 1.011 ± 0.065 and 3.498 ± 0.067 µM, respectively. The mode of action of propofol of inhibiting HSD3B was competitive when pregnenolone was added. At 50 µM, propofol did not directly inhibit rat and human testis CYP11A1, CYP17A1, and HSD17B3 activities in vitro. Conclusion: Propofol inhibits androgen production via both directly inhibiting HSD3B activity and down-regulating Cyp11a1 and Cyp17a1 expression in Leydig cells. Suppression of steroidogenic enzymes is presumably associated with the lower production of androgen by Leydig cells after propofol treatment. However, propofol-induced inhibition on androgen production is reversible.

Abstract 1612: The effect of docosahexaenoic acid on androgen-dependent and androgen-independent prostate tumors in combination with abiraterone and enzalutamide

Abstract Standard treatments for prostate cancer typically involve androgen deprivation therapy (ADT). In later stages of prostate cancer, the tumor typically evolves to become insensitive to ADT, otherwise known as castration-resistant prostate cancer (CRPC). Despite being hormone-insensitive, CRPC has been shown to respond to both abiraterone and enzalutamide. Although both treatments deprive the tumor of androgens, they both display different mechanisms of action. Abiraterone inhibits androgen production, and enzalutamide acts by interrupting the binding of androgens to the androgen receptor. Studies in our laboratory have shown that docosahexaenoic acid (DHA; C22:6, n-3), a long chain omega-3 polyunsaturated fatty acid (PUFA), inhibits tumorigenesis in both androgen-dependent (LNCaP) and androgen-independent (PC-3, DU145) prostate cancer cell lines in culture. Moreover, in vivo studies with n-3 supplementation have been shown to significantly reduce PC-3 and DU145 tumor growth compared to corn oil diets rich in linoleic acid (C18:2, n-6). With evidence suggesting that n-3 PUFA dietary supplementation can inhibit tumorigenesis in CRPC, this study investigated the efficacy of DHA in combination with both abiraterone and enzalutamide in a subset of prostate tumor phenotypes in vitro. PC-3 and LNCaP cell viability were reduced with DHA in combination with either enzalutamide or abiraterone compared to primary treatments of each. These results suggest that DHA enrichment can augment abiraterone and/or enzalutamide therapy with androgen-dependent and androgen-independent prostate tumors in vitro. The results of this study provide preliminary evidence of the effectiveness of nutritional supplementation in conjunction with cancer therapeutics, and it will serve as a prelude to a pilot clinical trial evaluating the effects of nutritional supplementation with high levels of omega-3 fatty acids on enzalutamide inhibition of CRPC. Citation Format: Andrew R. Cooper, Irvin V. Ma, Andy Shao, Prem Kumar, Ronald S. Pardini. The effect of docosahexaenoic acid on androgen-dependent and androgen-independent prostate tumors in combination with abiraterone and enzalutamide [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2019; 2019 Mar 29-Apr 3; Atlanta, GA. Philadelphia (PA): AACR; Cancer Res 2019;79(13 Suppl):Abstract nr 1612.

Towards cell therapy of polycystic ovary syndrome (PCOS): human mesenchymal stem cells secretome inhibits androgen production by pcos theca cells

Background & Aim Background Polycystic Ovarian Syndrome (PCOS) is a metabolic disorder characterized by inflammation, infertility and excess ovarian androgen production by theca cells. Though its etiology is not fully understood. Women with PCOS exhibit increased expression of CYP17A1, and CYP11A1 genes involved in androgen production. Due to the robust anti-inflammatory ability of human bone marrow Mesenchymal stem cells (hMSCs), we evaluated its utility as a novel cell-therapy by injecting hMSCs directly into the ovaries of PCOS mouse model. It showed a significant improvement in hyperandrogenemia. hMSCs also secrete various factors in media, known as secretome. The literature shows that the secretome of hMSCs has the same regenerative and reparative function likes hMSCs. Hypothesis We hypothesize that hMSCs secretome contains the factors that are able to inhibit the androgen biosynthesis in PCOS theca cells. Methods, Results & Conclusion Material and Methods Theca cells, collected from normal cycling and PCOS patient underwent ovariectomy, were seeded on culture dishes pre-coated with the extracellular matrix at a density of 6 × 104 cells/ml and cultured for 24 hours. Cells were then treated with either 3T3 conditioned media as a control (C) or Mesenchymal stem cells conditioned media (CM). The C and CM were prepared through collecting the serum-free supernatant of 3T3 and hMSCs at an optimal confluence, 48 hours later. The mRNA and protein expression of CYP17A1, CYP11A1, and DENND1A.V2 were quantified by RT-PCR and Western blot, while testosterone level in media was measured by RIA assay. Results Human PCOS theca cells treated with hMSCs CM for 48 hours secreted significantly lower level of testosterone (146 ± 13.6 ng/dl) compared to control C (215 ± 11.3 ng/dl) (P Conclusion The therapeutic capabilities of hMSCs in PCOS are partially mediated by its secretome which contains various growth factors and anti-inflammatory cytokines both free and within extracellular vesicles. Stem cell therapy, either by cell implantation or via secretome injection might potentially be a novel approach for effective treatment of PCOS patients.

SUN-LB002 CYP11A1 Inhibition as a Therapeutic Approach for the Treatment of Castration Resistant Prostate Cancer

Background: Prostate cancer is a major global challenge due to the increasing number of aging population and frequency of diagnosis. During the past decade new treatments have been targeted to the androgen signaling axis either by inhibiting the binding of androgens to androgen receptor (AR) and AR nuclear translocation, or by inhibiting androgen production via CYP17A1 enzyme. Despite the significant progress on the research and new therapies, CRPC is still incurable and there is urgent need for better, more effective treatments. ODM-208 is an oral, non-steroidal and selective inhibitor of CYP11A1 enzyme, suppressing the synthesis of all steroid hormones that could be potential agonistic AR ligands. Methods: The inhibition of CYP11A1 was measured in vitro by the formation of radiolabelled isocapronic acid in a human adrenal cortex cell line (H295R). The tumor growth inhibition of ODM-208 was studied in VCaP castration-resistant prostate cancer (CRPC) xenograft model. At the end of the xenograft study, plasma ACTH and LH, and key steroid hormone concentrations were analysed from plasma and target tissues. In addition, full length AR (AR-FL) and AR-V7 were analysed from the tumors by western blot and key enzymes of androgen biosynthesis, CYP17A1, AKR1C3, SRD5A1 were quantified by qPCR. In dogs an ACTH stimulation test was done. Results: ODM-208 potently inhibits CYP11A1 enzyme in vitro. In addition, in vivo in the VCaP CRPC xenograft model ODM-208 significantly inhibited tumor growth. Importantly, the amount of AR-FL and AR-V7 levels remained unchanged in the tumors after ODM-208 treatment. Slight increase of CYP17A1 and SRD5A1 enzyme levels was observed, indicating the activation of steroidogenesis in VCaP tumors in vivo. Treatment had no effect on plasma LH, whereas ACTH was significantly increased demonstrating reduction in glucocorticoid levels by negative feedback. In line with ACTH, all measured steroid hormones were significantly reduced both in plasma and target tissues. In dogs ACTH-stimulated cortisol production was significantly inhibited after single oral dose of ODM-208. Conclusions: ODM-208 shows promising antitumor activity in preclinical CRPC models and has favorable toxicological profile. Thus, ODM-208 might have potential for treating patients with CRPC. Based on the nonclinical results, a phase 1/2 clinical trial has been initiated. Unless otherwise noted, all abstracts presented at ENDO are embargoed until the date and time of presentation. For oral presentations, the abstracts are embargoed until the session begins. s presented at a news conference are embargoed until the date and time of the news conference. The Endocrine Society reserves the right to lift the embargo on specific abstracts that are selected for promotion prior to or during ENDO.

Theca cells and the regulation of ovarian androgen production

Theca cells are essential for female reproduction being the source of androgens that are precursors for follicular oestrogen synthesis and also signal through androgen receptors (AR) in the ovary and elsewhere. Theca cells arise from mesenchymal cells around the secondary follicle stage. Their recruitment, proliferation and cytodifferentiation are influenced, directly or indirectly, by paracrine signals from granulosa cells and oocyte although uncertainty remains over which are the critically important signals at particular stages. In a reciprocal manner, theca cells secrete factors that influence granulosa cell proliferation and differentiation at different follicle stages. Differentiated theca interna cells acquire responsiveness to luteinizing hormone (LH) and other endocrine signals and express components of the steroidogenic machinery required for androgen biosynthesis. They also express insulin-like peptide 3 (INSL3) and its receptor (RXFP2), levels of which increase during bovine antral follicle development. INSL3 signaling may play a role in promoting androgen biosynthesis since knockdown of either INSL3 or its receptor (RXFP2) in bovine theca cells inhibits androgen biosynthesis while exogenous INSL3 can raise androgen secretion. Bone morphogenetic proteins (BMPs) of thecal or granulosal origin suppress thecal production of both INSL3 and androgen. Inhibin, produced in greatest amounts by granulosa cells of preovulatory follicles, reverses these BMP actions. Thus, BMP-induced inhibition of thecal androgen production may be mediated by reduced INSL3-RXFP2 signaling. Activins also inhibit androgen production in an inhibin-reversible manner and recent evidence in sheep indicates that theca cells synthesize and secrete activin, implying an autocrine role in suppressing androgen biosynthesis in smaller follicles, akin to that envisaged for BMPs.

Effect of glucocorticoids on androgen biosynthesis in the testes of the toad Rhinella arenarum (Amphibia, Anura)

In rat Leydig cells, glucocorticoids (GCs) inhibit testosterone production through the interaction with the glucocorticoid receptor (GR). However, the sensitivity of those cells to GCs is regulated by the enzyme 11β-hydroxysteroid dehydrogenase Type 1 (11β-HSD1). In the testes of the toad Rhinella arenarum, the presence of an 11β-HSD similar to type 2 and a cytosolic GR has also been described. However, there is a lack of information regarding the effects of GCs on amphibian testicular steroidogenesis. In this study, the effects of corticosterone on androgen production, and the activity of two steroidogenic enzymes in toad testes were reported. Corticosterone inhibits androgen production via the GR because the GR antagonist RU486 prevents corticosterone-induced inhibition of testosterone. Corticosterone also reduced the activity of the cytochrome P450 17-hydroxylase, C17,20-lyase (Cyp450 c17 ) without affecting the 3β-hydroxysteroid dehydrogenase/isomerase activity. This effect on Cyp450 c17 was likewise inhibited by RU486. On the other hand, corticosterone had no effect on the amount of steroidogenic acute regulator protein. These results suggest that GCs inhibit steroidogenesis in toad testes by reducing of Cyp450 c17 activity via a GR-mediated mechanism.

4-Bromodiphenyl ether delays pubertal Leydig cell development in rats

Polybrominated diphenyl ethers are a class of brominated flame retardants that are potential endocrine disruptors. 4-Bromodiphenyl ether (BDE-3) is the most abundant photodegradation product of higher polybrominated diphenyl ethers. However, whether BDE-3 affects Leydig cell development during puberty is still unknown. The objective of this study was to explore effects of BDE-3 on the pubertal development of rat Leydig cells. Male Sprague Dawley rats (35 days of age) were gavaged daily with BDE-3 (0, 50, 100, and 200 mg/kg body weight/day) for 21 days. BDE-3 decreased serum testosterone levels (1.099 ± 0.412 ng/ml at a dose of 200 mg/kg BDE-3 when compared to the control level (2.402 ± 0.184 ng/ml, mean ± S.E.). BDE-3 decreased Leydig cell size and cytoplasmic size at a dose of 200 mg/kg, decreased Lhcgr, Star, Dhh, and Sox9 mRNA levels at ≥ 100 mg/kg and Scarb1, Cyp11a1, Hsd17b3, and Fshr at 200 mg/kg. BED-3 also decreased the phosphorylation of AKT1, AKT2, ERK1/2, and AMPK at 100 or 200 mg/kg. BDE-3 in vitro induced ROS generation, inhibited androgen production, down-regulated Lhcgr, Scarb1, Star, Cyp11a1, Hsd3b1, Srd5a1, and Akr1c14 expression in immature Leydig cells after 24-h treatment. In conclusion, the current study indicates that BDE-3 disrupts Leydig cell development via suppressing AKT, ERK1/2, and AMPK phosphorylation and inducing ROS generation.

Lambda-cyhalothrin delays pubertal Leydig cell development in rats

Lambda-cyhalothrin (LCT) is a widely used broad-spectrum pyrethroid insecticide and is expected to cause deleterious effects on the male reproductive system. However, the effects of LCT on Leydig cell development during puberty are unclear. The current study addressed these effects. Twenty-eight-day-old male Sprague Dawley rats orally received LCT (0, 0.25, 0.5 or 1 mg/kg body weight/day) for 30 days. The levels of serum testosterone, luteinizing hormone, and follicle-stimulating hormone, Leydig cell number, and its specific gene and protein expression were determined. LCT exposure lowered serum testosterone levels at doses of 0.5 and 1 mg/kg and luteinizing hormone levels at a dose of 1 mg/kg, but increased follicle-stimulating hormone levels at doses of 0.5 and 1 mg/kg. LCT lowered Star and Hsd3b1 mRNA or their protein levels at a dose of 1 mg/kg. Immature Leydig cells were purified from pubertal rats and treated with different concentrations of LCT for 24 h and medium androgen levels, Leydig cell mRNA and protein levels, the mitochondrial membrane potential (△Ψm), and the apoptotic rate of immature Leydig cells were investigated. LCT inhibited androgen production at 5 μM and downregulated Scarb1 at 0.05 μM, Hsd3b1 and Hsd11b1 at 0.5 μM, and Cyp11a1 at 5 μM. LCT also decreased △Ψm at 0.5 and 50 μM. In conclusion, LCT can influence the function of Leydig cells.